This invention relates to a dynamic random access memory (RAM) and a semiconductor device and more particularly, the invention relates to an effective technique using a so-called one cross point method where a dynamic memory cell is arranged at a cross point of a word line and a bit line.
According to a search conducted after this invention was made, some publications which might be related to the technology of the present invention, to be described later as an open bit line type (or one cross point method) dynamic RAM, were found, including Japanese Patent Laid-Open No. 206991/1988 (related art 1, hereinafter), Japanese Patent Laid-Open No. 13290/1989 (related art 2, hereinafter), U.S. Pat. No. 5,608,668 (related art 3, hereinafter), and Japanese Patent Laid-Open No. 41081/1993 (related art 4, hereinafter). According to related arts 1 and 2, one sense amplifier is fitted into a pitch for two bit lines by positioning-sense amplifies alternately, based on the open bit line method (one-cross point method). According to related arts 3 and 4, there is provided a circuit achieving, based on an electrical model which is substantially the same as a bit line, for achieving a reference voltage required for an operation by a sense amplifier provided at an end portion in a case where sense amplifiers are positioned alternately for more efficient use of a chip area, as in the related arts 1 and 2.